Field-assisted combustion synthesis of MoSi2-SiC composites

Abstract

No investigation on the use of self-propagating high-temperature synthesis (SHS) to prepare MoSi[sub 2]/SiC composites has been reported. Reactions to synthesize such composites from elemental powders are not strongly energetic and thus cannot become self-sustaining without the pre-heating of the reactants. The adiabatic combustion temperature of MoSi[sub 2] is 1,900 K, which is at the empirically defined boundary between the occurrence and absence of SHS reactions. Since the adiabatic temperature of SiC is 1,800 K, that of the composite MoSi[sub 2] + x SiC is less than 1,900 K for any value of x. Through the application of an electric field, the authors have recently been successful in forming a variety of materials which are difficult or impossible to prepare by SHS. They report here the results of the first demonstration of the use of SHS to prepare MoSi[sub 2] + x SiC composites for 0 [le] x [le] 1.0.